The invention relates to an intake system for an internal combustion engine, especially for a motor vehicle engine according to the preamble of the main claim.
German OS 41 10 597 discloses an intake system for a multicylinder internal combustion engine which is configured as an intake system. In such an air intake system a plurality of intake tubes is required, which feed the cleaned aspirated air from a manifold passage to the individual aspirating ports in the cylinder head of the engine. The intake system consists usually of aluminum or synthetic resin material and is made by casting or injection molding.
A disadvantage of such systems consists in the complicated manufacturing process. For example, it is known to manufacture an intake system by the core melting process, wherein a metal core, which forms the later cavities of the system, is encased in synthetic resin material and this metal core is then melted out. It is also possible to make such an air intake system of synthetic resin material by the multiple shell technique, that is, to form individual synthetic resin shells and weld them together.
The invention is addressed to the problem of avoiding the described disadvantages and of creating an intake system which is simple to manufacture and involves no great expense in assembly. This problem is solved by the characteristics of the main claim.
The core idea of the invention is to make the very irregularly shaped air intake tubes, which considerably complicate the manufacturing process, of one or more blow-molded parts and fasten these parts with flange elements or additional synthetic resin components which have a simple structure. In fastening the blow-molded part with a connecting flange and other elements it is possible to make the junction non-transmissive of vibration. This means that, between the two elements to be joined, an elastomeric composition is installed by an assembly injection molding process. This elastomeric composition produces on the one hand a reliable junction between the two elements. On the other hand it decouples this element with regard to the transmission of vibrations.
An additional advantage in the use of blow-molded parts is that the vibration tube lengths can be made variable, that is, optimization is possible without great effort.
A preferred embodiment of the invention provides for making the elements not made by the blow-molding of synthetic resin material by the injection molding method out of thermoplastic synthetic resin material.
According to an embodiment of the invention, furthermore, an additional connection to one or more suction pipes is provided, making this connection for coupling to or uncoupling from a switching means. With the additional connection the possibility is offered of providing the intake system with an additional duct which can be opened and closed depending on the speed of the motor and its load.
In order to produce a highly precise synthetic resin component, the possibility exists of making it from glass fiber reinforced thermoplastic synthetic resin, the glass fibers being so-called long fibers. These long fibers have the advantage that they embed themselves anisotropically in the synthetic resin material and thus the tensional performance of the synthetic resin material is isotropic. Preferably, polypropylene or polyamide can be used as synthetic resin material. As a result of the simple production of the collecting unit, additional elements can be integrated therein, such as throttle valve, air volume meters and other necessary components.
These and other features of preferred embodiments of the invention will appear not only from the claims but also from the description and the drawings, the individual features being able to be embodied individually or plurally in the form of sub-combinations in the embodiment of the invention and in other fields, and can be advantageous as well as independently patentable embodiments for which protection is hereby claimed.
Embodiments of the invention are represented in the drawings and are further explained hereinbelow.
The drawings show: